<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>JavaScript</title>
</head>
<body>
    
</body>
<script type="text/javascript">
    document.write("使用JavasScript脚本语言循环输出hello world!")
    for(var i=0;i<3;i++){
        document.write("<h1>hello world!</h1>")
    }
</script>
</html>